Among the filamentous fungi, in particular, Aspergillus including Aspergillus oryzae (yellow Aspergillus) etc. has been traditionally used in brewing industry in Japan for producing sake, bean paste, soy sauce, mirin, and the like, and directly eaten. Aspergillus is a safe source of genes listed up in GRAS (Generally Recognized as Safe) of US FDA (Food and drug Administration).
Therefore, in the safety test such as a chronic toxicity test required when genes derived from general fungi are used for foods, etc., in the case of genes derived from general fungi, the cost is about 1 billion yen. On the other hand, in the case of genes that are the above-mentioned GRAS genes, it is advantageous that the cost can be made to be about one-third of the cost and further that it takes a shorter time to conduct the test as compared with the case of general genes.
Thus, filamentous fungi, in particular, Aspergillus could provide a treasure trove of genes with a high utility value from the safe and economical viewpoint. The technology related to the present invention is disclosed in Japanese Patent No. 2796114 (patent document 1) and Japanese Patent No. 2977245 (patent document 2).